1. Field of the Invention
The present invention relates to a light-emitting-diode (LED) protection circuit, and in particular to a multi-function protection circuit of Over Voltage Protection (OVP), Over Current Protection (OCP), Over Temperature Protection (OTP), and Lightning Protection, realized through using fuse elements and discharge protection elements.
2. The Prior Arts
Nowadays, due to the ever increasing price of oil, the ample supply of energy resources and materials is an important issue, therefore, how to conserve consumption of energy and materials is a major target of Industries. Wherein, the energy used by the illumination devices occupies quite a large percentage of total energy consumption, thus it is now an important item for energy conservation. Compared with the conventional incandescent light bulb and fluorescent light tube, the light-emitting-diode has various advantages, such as compact size (multiple units, multiple combinations), low heat generation (low heat radiation), low electricity consumption (low starting voltage and current), long service life (more than 100,000 hours), fast response speed (can be operated at high frequency), environment friendly (shock proof, not easy to be broken upon impact, recoverable, and pollution free), so that it can be packaged in a planar way, and is easy to be made into products of light weight, compact size, and thin profile. As such, with the increased brightness and reduced cost of LED, it now has wider scope of applications, such that it can be used widely in various illumination devices, such as white light illumination device, indication lamps, vehicle signal lights, vehicle head lights, flashing light, backlight module of liquid crystal display (LCD), light source of projector, and outdoor displaying units.
Presently, most of the power used by the electrical appliances and electronic products is supply by the Local Power Company, and that is transmitted through transmission lines made of metal, as such it is very likely to be stricken by lightning. In addition to its over current, the high voltage incurred usually is the main reason for causing damages to the electrical appliances and electronic products. In this respect, an LED product is taken as an example for explanation, that is driven by AC power supply (local Utility power), and during which instantaneous over current is likely to be produced by instantaneous high voltage (spike), thus damaging the LED products and reducing its service life.
Therefore, presently, the problem of how to protect LED products from being damaged by Over Current, Over Voltage, Over Temperature, spike, and lightning is an urgent task, that has to be solved in this field.